Wastewater Purification Research Articles

BiOClxM1-x (M=I, Br) solid solution-coupled CdS photocatalysts for enhancing visible light-driven organic pollutants degradation with simultaneous hydrogen production

The construction of Z-scheme heterojunction stands out as one of the most effective modification methods for enhancing the performance of photocatalysts. Therefore, BiOClxM1-x (M=I, Br) solid solution-coupled CdS (BiOClxM1-x/CdS) Z-scheme photocatalysts were successfully synthesized by a hydrothermal-precipitation method. BiOCl0.8I0.2/CdS exhibited notable photocatalytic performance with a hydrogen yield of 261 μmol/g, which was 2.23, 1.56 and 1.44 times higher than that of CdS, BiOCl/CdS and BiOCl0.5Br0.5/CdS, respectively. This improvement can be attributed to two key factors: (1) the formation of BiOClxM1-x (M=I, Br) solid solution enhances visible light absorption; (2) The formation of BiOCl0.8I0.2/CdS (M=I, Br) Z-scheme heterojunctions inhibit the recombination of photogenerated carriers to prolong the lifetime of photogenerated carriers, thus increasing the utilization of the photogenerated carriers. Moreover, BiOCl0.8I0.2/CdS also showed good photocatalytic activity in ROW-DFHP (residual organic wastewater from dark fermentation for hydrogen production), with a hydrogen production rate of 42.83 μmol/g and a mineralization rate of organic pollutants of 31.73%. Cycling experiments, XRD and SEM of the samples before and after the photocatalytic reaction showed that BiOCl0.8I0.2/CdS has good stability. Furthermore, the mechanism of BiOCl0.8I0.2/CdS for the photocatalytic degradation of organic pollutants and simultaneous hydrogen production was proposed, offering a novel strategy for organic wastewater purification and hydrogen energy recovery.

Application and mechanism of carbonate material in the treatment of heavy metal pollution: a review.

Among the many heavy metal pollution treatment agents, carbonate materials show strong flexibility and versatility by virtue of their high adsorption capacity for heavy metals and the characteristics of multiple and simple modification methods. It shows good potential for development. This review summarizes the application of carbonate materials in the treatment of heavy metal pollution according to the research of other scholars. It mainly relates to the application of surface-modified, activated, and nano-sized carbonate materials in the treatment of heavy metal pollution in water. Natural carbonate minerals and composite carbonate minerals solidify and stabilize heavy metals in soil. Solidification of heavy metals in hazardous waste solids is by MICP. There are four aspects of calcium carbonate oligomers curing heavy metals in fly ash from waste incineration. The mechanism of treating heavy metals by carbonate in different media was discussed. However, in the complex environment where multiple types of pollutants coexist, questions on how to maintain the efficient processing capacity of carbonate materials and how to use MICP to integrate heavy metal fixation and seepage prevention in solid waste base under complex and changeable natural environment deserve our further consideration. In addition, the use of carbonate materials for the purification of trace radioactive wastewater and the safe treatment of trace radioactive solid waste are also worthy of further exploration.

Synergistically interface networked organic–inorganic photocatalytic membrane for highly stable Cr(VI) reduction and hydrogen production

Artificial conversion technology based on solar energy is one of most strategic artificial technologies for addressing environmental hazards and energy crisis. However, micro/nano-sized particulate catalysts mostly have the drawbacks of unstable microstructure and difficult recovery, which inevitably limits the practical application of photocatalysis technology. In order to overcome the defects of most inorganic particulate photocatalysts, a novel organic–inorganic photocatalytic membrane based on highly active Bi4Ti3O12/CdS composite and polyvinylidene fluoride (PVDF) was processed for simulated sunlight (SSL)-driven Cr(VI)-to-Cr(III) (CTC) reduction and H2O-to-H2 (HTH) conversion. Due to the maximum light harvesting capacity and synergistically electronic interaction of this synergistically interface networked organic–inorganic membrane, it possesses accelerated dynamics for separating/transferring photoexcitons and restraining photoexciton recombination, thereby outstanding CTC reduction rate (1.25 × 10-2 min−1) and HTH conversion rate (7.45 mmol∙m−2∙h−1) were achieved under SSL-irradiation, and highly stable photoactivity was maintained even being recycled for dozens of times owing to the convenient separation/recovery performance and stable organic–inorganic matrix. Subsequently, a panel reactor for wastewater purification was constructed to achieve 6.5 × 10-3 min−1 of CTC reduction rate under SSL-irradiation. This study provides a prospective insight for application of photocatalysis technology based on the membrane materials.

Hydrothermal synthesis of high crystallinity ZSM-5 zeolite from coal gasification coarse slag and mother liquor circulation for efficient coal chemical wastewater purification.

A hydrothermal synthesis method was developed to produce high crystallinity ZSM-5 zeolite using coal gasification coarse slag (CGCS) as the raw material. Instead of the expensive NaOH(s.), Na2SiO3(s.) was utilized to activate, depolymerize, and recombine Si and Al elements in the CGCS. The mother liquor circulation technology was employed to recover and reuse raw materials and residual reagents (Na2SiO3(aq.) and TPABr), reducing waste emissions and enhancing resource utilization efficiency. The synthesized ZSM-5 had a specific surface area of 455.675 m2g-1, pore volume of 0.284 cm3g-1, and pore diameter of 2.496nm. The influence of various factors on the morphology and crystallinity of ZSM-5 was investigated, resulting in the production of ZSM-5 with higher specific surface area and pore volume. Adsorption experiments showed that WU-ZSM-5 exhibited a removal efficiency of 85% for ammonia nitrogen (NH4+-N(aq.)), validating its effectiveness in coal chemical wastewater purification. The mother liquor recycling technology enabled zero-emission utilization of solid waste resources and improved the utilization rate of alkali and template to 90%. These results demonstrate the potential application of the developed method in the efficient treatment of coal chemical wastewater.

Effects of different flocculants and environment on the flocculation effect of potato starch-processing wastewater

ABSTRACT Potato starch-processing wastewater belongs to high-concentration organic wastewater, as direct discharge is more polluting to the environment. Flocculation treatment, as the initial process of wastewater purification, can remove large debris in wastewater, reduce energy consumption for subsequent treatment and reduce production costs. In this study, the effects of traditional flocculants and biological flocculants on the treatment of potato starch-processing wastewater under different pH, dosage, stirring rate and settling time were studied. It was found that traditional flocculants and biological flocculants have their own advantages in the purification ability of organic matter, and the removal rates of suspended solids (SS) and total phosphorus (TP) of traditional flocculants are better than biological flocculants for sweet potato starch-processing wastewater, but the flocculation time and settling time are long. Biological flocculants are environmentally friendly, safe and non-polluting, and do not produce secondary pollution when the flocculation treatment of wastewater is conducive to the secondary reuse of wastewater and flocculation sediment resource treatment. According to the flocculation effect and cost, chitosan is the best flocculant for treating sweet potato starch-processing wastewater.

Preparation of Newly Polymer-Coated Microbial Pellets and Their Adsorption and Degradation Properties for Oil-Containing Wastewater.

Water is the lifeblood of everything on earth, nourishing and nurturing all forms of life, while also contributing to the development of civilization. However, with the rapid development of economic construction, especially the accelerated process of modern industrialization, the pollution of oily sewage is becoming increasingly serious, affecting the ecological balance and human health. The efficient elimination of pollutants in sewage is, therefore, particularly urgent. In this paper, a core-shell microbial reactor (MPFA@CNF-SA-AM) was fabricated by using nanocellulose and sodium alginate (SA) particles embedded with microorganisms as the core and lipophilic and hydrophobic fly ash as the outer shell layer. Compared with that of free microorganisms and cellulose and SA aerogel pellets loading with microorganisms (CNF-SA-AM), which has a degradation efficiency of 60.69 and 82.89%, respectively, the MPFA@CNF-SA-AM possesses a highest degradation efficiency of 90.60% within 240 h. So that this self-floating microbial reactor has selective adsorption properties to achieve oil-water separation in oily wastewater and high effective degradation of organic pollutants with low cost. The adsorption curves of MPFA@CNF-SA-AM for diesel and n-hexadecane were studied. The results showed that the adsorption follows the Freundlich model and is a multimolecular layer of physical adsorption. In addition, the degradation mechanism of diesel oil was studied by gas chromatography-mass spectrometry. The results showed that diesel oil was selectively adsorbed to the interior of MPFA@CNF-SA-AM, and it was degraded by enzymes in microorganisms into n-hexadecanol, n-hexadecaldehyde, and n-hexadecanoic acid in turn, and finally converted to water and carbon dioxide. Compared with existing oily wastewater treatment methods, this green and pollution-free dual-functional core-shell microbial reactor has the characteristics of easy preparation, high efficiency, flexibility, and large-scale degradation. It provides a new, effective green choice for oily wastewater purification and on-site oil spill accidents.

Superhydrophilic PANI/Ag/TA@PVDF Composite Membrane with Antifouling Property for Oil-Water Separation.

The current membrane materials used for oil-water separation suffer from low separation efficiency and poor durability, and membrane contamination is also a key issue that must be addressed urgently. In this paper, a superhydrophilic PANI/Ag/TA@PVDF composite membrane with PANI-Ag NPs heterojunction structure was prepared via chelation and reduction of Ag+ by tannic acid (TA) and in situ growth of hydrochloric acid-doped polyaniline (PANI). TA endows the prepared composite membrane with excellent superhydrophilicity and underwater oleophobicity, remarkable oil-water separation capacity (the separation efficiency of more than 97% for soybean oil), and extraordinary antifouling properties. Notably, the range of photodegradation is expanded from UV to visible light by the construction of a Schottky heterostructure between PANI and Ag NPs, the photocatalytic degradation ability of composite membrane for organic pollutants has been improved obviously, and the degradation efficiency for crystal violet (CV) is 97.9%. Considering these merits, the PANI/Ag/TA@PVDF composite membrane provides an effective strategy to overcome the shortcomings of existing membrane materials, presenting enormous potential in the treatment and purification of oily wastewater.

Three-dimensional NiO/Ni self-floating porous composite materials for efficient solar interfacial evaporation

The scarcity of freshwater resources and energy crisis are major challenges to the progress of human society. Recently, solar-driven interfacial water evaporation utilizes photothermal conversion materials to convert solar energy into thermal energy, which possesses great application potential in seawater desalination and sewage treatment. Here, we fabricated porous nickel sponge (NSP) composite photothermal material (NiO-NSP) containing abundant NiO nanoneedles array. This in situ-grown NiO with enhanced bonding between photothermal material and substrate can be used as a solar absorber directly without consuming additional photothermal material compared to conventional coating and cladding on the carrier surface. Due to the multi-scattering induced light trapping effect of the semiconductor NiO nanoneedles array on the surface of nickel fibers, resulting in light absorption up to 96.5 %. NiO-NSP evaporators have an abundance of interconnected porous channels for water supply, which results in strong capillary action to pump water to the evaporation interface efficiently. Moreover, the highly dispersed nanoneedles array expand the evaporation surface area. Consequently, the NiO-NSP evaporator delivers an excellent evaporation rate of 1.78 kg m−2 h−1 and a photothermal conversion efficiency of 84.7 % at one sun radiation. In addition, the micron-sized porous mesh structure of NiO-NSP dissolve salt crystals and diffuse them downward into the bulk brine, exhibiting excellent salt resistance and remarkable seawater desalination stability. Moreover, NiO-NSP solar evaporators has been demonstrated to possess excellent ability to purify dye and heavy metal ion wastewater. Therefore, the NiO-NSP high-performance evaporator produced by straightforward process proved to be suitable for solar seawater desalination and wastewater purification.

The Multifaceted Effects of Non-Steroidal and Non-Opioid Anti-Inflammatory and Analgesic Drugs on Platelets: Current Knowledge, Limitations, and Future Perspectives.

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely utilized pharmaceuticals worldwide. Besides their recognized anti-inflammatory effects, these drugs exhibit various other pleiotropic effects in several cells, including platelets. Within this article, the multifaceted properties of NSAIDs on platelet functions, activation and viability, as well as their interaction(s) with established antiplatelet medications, by hindering several platelet agonists' pathways and receptors, are thoroughly reviewed. The efficacy and safety of NSAIDs as adjunctive therapies for conditions involving inflammation and platelet activation are also discussed. Emphasis is given to the antiplatelet potential of commonly administered NSAIDs medications, such as ibuprofen, diclofenac, naproxen and ketoprofen, alongside non-opioid analgesic and antipyretic medications like paracetamol. This article delves into their mechanisms of action against different pathways of platelet activation, aggregation and overall platelet functions, highlighting additional health-promoting properties of these anti-inflammatory and analgesic agents, without neglecting the induced by these drugs' side-effects on platelets' functionality and thrombocytopenia. Environmental issues emerging from the ever-increased subscription of these drugs are also discussed, along with the need for novel water treatment methodologies for their appropriate elimination from water and wastewater samples. Despite being efficiently eliminated during wastewater treatment processes on occasion, NSAIDs remain prevalent and are found at significant concentrations in water bodies that receive effluents from wastewater treatment plants (WWTPs), since there is no one-size-fits-all solution for removing all contaminants from wastewater, depending on the specific characteristics of the wastewater. Several novel methods have been studied, with adsorption being proposed as a cost-effective and environmentally friendly method for wastewater purification from such drugs. This article also presents limitations and future prospects regarding the observed antiplatelet effects of NSAIDs, as well as the potential of novel derivatives of these compounds, with benefits in other important platelet functions.

Unveiling the Geological Significance and Industrial Application of Limestone: A Comprehensive Review

Limestone emerges as a fundamental component within sedimentary rock formations, which provides important information about previous geological eras and environmental circumstances. It retains fossils and remnants of extinct living forms because it mostly contains calcium carbonate. These deposits are used as traces of freshwater, marine, and terrestrial habitats from the past. Furthermore, variations in the creation of limestone provide hints about past geological events like tectonic activity and sea level shifts. Scientists can reconstruct previous ecosystems, temperatures, and evolutionary patterns by analyzing limestone, which helps us better comprehend Earth's environmental dynamics and history over millions of years. Its versatility extends beyond its geological significance, and its primary uses are in the manufacturing of steel and cement, as well as in the purification of wastewater and the processes involved in the production of bread and sugar. Limestone is also essential for supporting the carbon cycle and improving soil health in agricultural settings. In the review paper, we endeavored to conduct additional research to comprehend the intricacies of geology and the industrial application of limestone, as well as the need for interdisciplinary collaboration, sustainable practices, and cutting-edge technologies to leverage mineral resources for industrial growth. To be effective, it is essential. This study concludes with a strong call to action, imploring stakeholders to emphasize sustainable practices and encourage interdisciplinary collaboration while using limestone. By adhering to these guidelines, we can maximize the benefits of this priceless natural resource for both industrial use and environmental sustainability while also protecting it for future generations.

Pomelo peel biomass derived highly active advanced-oxidation-process catalyst: Complete elimination of organic pollutants

The advanced oxidation process (AOPs) is playing an important role in the elimination of hazardous organic pollutants, but the development of inexpensive and highly active advanced catalysts is facing challenges. In this study, a low-cost and readily available agricultural waste resource pomelo peel-flesh (PPF) biomass was used as the basic raw material, and the uniformly dispersed small cobalt nanoparticles were effectively anchored in the biochar derived from pomelo peel-flesh (BDPPF) by impregnation adsorption/complexation combined with heat treatment. Co/BDPPF (BDPPF embedded with Co) can effectively activate peroxymonosulfate (PMS) to SO4·-, ·OH and 1O2 reactive oxygen species, and achieve nearly 100% degradation of tetracycline persistent organic pollutant. Co/BDPPF can not only degrade tetracycline efficiently in complex water environment, but also degrade most organic pollutants universally, and has long-term stability, which solves the problem of poor universality and stability of heterogeneous catalysts to a certain extent. Importantly, Co/BDPPF derived from waste biomass was also innovatively designed as the core of an integrated continuous purification device to achieve continuous purification of organic wastewater. In this study, agricultural waste resources were selected as biomass raw materials to achieve efficient capture of Co2+, and finally developed advanced AOPs catalyst with excellent performance to achieve the purification of organic wastewater. It also provides a promising solution for the preparation of simple, low-cost, large-scale production of AOPs catalysts that can be put into actual production.

Synthesis, utilization, and recycling of graphene oxide-based nanohybrid biopolymeric hydrogels for purification of dye wastewater

ABSTRACT Wastewater from industries contributes significantly to pollution. Adsorption of acidic dye using nanohybrid biopolymeric hydrogels has evolved as one of the viable techniques. Graphene oxide (GO)/chitosan (CS)–polyvinyl alcohol (PVA), GO/starch–PVA, and GO/agar–PVA hydrogels were synthesized. The results revealed that the following are the ideal values: GO/CS–PVA: 3 pH (8.251 mg g−1), 0.05 g/50mL dosage (8.251 mg g−1), 90 min (8.251 mg g−1), 12 ppm dye concentration (8.251 mg g−1), and 30 °C (8.251 mg g−1); for GO/starch–PVA: 2 pH (7.437 mg g−1), 0.05 g/50 mL dosage (7.437 mg g−1), 90 min (7.437 mg g−1), 12 ppm dye concentration (7.437 mg g−1), and 30 °C (7.437 mg g−1); and for GO/agar–PVA; 3 pH (6.142 mg g−1), 0.05 g/50 mL dosage (6.142 mg g−1), 90 min (6.142 mg g−1), 12 ppm dye concentration (6.142 mg g−1), 30 °C (6.142 mg g−1). GO/CS–PVA outperformed the other hydrogels. The Langmuir model suited GO/CS–PVA data, while GO/starch–PVA and GO/agar–PVA hydrogels followed Freundlich isotherm models. The adsorption capacity data followed a pseudo-second-order model. Negative value of Gibbs free energy and enthalpy showed that the reactions were spontaneous and exothermic in nature. The presence of heavy metals, electrolytes, and detergents/surfactants affected the dye adsorption. Entropy changes positive values implied randomness at the solid/solution contact. The desorption (60, 55, and 58%) of GO/CS–PVA, GO/starch–PVA, and GO/agar–PVA hydrogels was obtained using 0.5 N NaOH. Scanning electron microscope, X-ray diffraction, and Fourier transform infrared (FT-IR) were used for characterization.

Wastewater purification and recycling using plants in an arid environment for agricultural purposes: case of the Algerian Sahara

The aim of this study is to apply a water treatment technique (phyto-purification) in the Algerian Sahara, an arid region, to resolve the scarcity of irrigation, recycled wastewater and preserve Saharian ecosystems composed of sand and two species of aquatic plants: Typha latifolia and Imperata cylindrica. The choice of these plants was determined based on the natural vegetation, soil and climatic characteristics of the study area. To this end, we developed an experimental pilot composed of three tanks measuring 30 cm × 35 cm × 45 cm, arranged with a filter bed of sand and gravel. Two of these tanks are sown with the above-mentioned plants, while the third tank, serving as a control, is not. The values of the main wastewater pollution parameters, namely total nitrogen compounds, ammonium (NH4+), chemical oxygen demand (COD) and suspended solids measured at the outlet of the device, substantiate the performance of this treatment system. Indeed, the nitrogen reduction rate increased from 63% in the unplanted control filters to around 80% in the planted filters, and from 81 to 88% for NO3−. Regarding chemical oxygen demand (COD), the reduction rate exceeds 88.37% for the three tanks. The study of the analytical approach to modeling the purification kinetics reveals that the kinetics of COD and NH4+ are well correlated with the first-order model, with an explained variance varying between 68.1 and 81.6% for COD and 83.5 and 92.3% for ammonium. The Riverside diagram highlights that all treated water samples fall into the low sodium risk and high salinity risk class. Build on the Na% values; all purified waters have characteristics suitable for water use for irrigation.

MoS2@ZIF-8-based aerogel with multiscale biomimetic structure achieving all-day desalination and wastewater purification

In emerging freshwater generation strategy, solar driven evaporation technology has been brought into focus owing to its non-pollution and facile facilities. However, maintaining high freshwater yield remains a challenge under natural circumstances. Herein, MoS2@ZIF-8-based aerogel featuring a lotus root hourglass-shaped structure (denoted as LMZA) for efficient freshwater production via hybrid energy harvesting is ingeniously devised. After being integrated with metallic 1 T phase MoS2 and a vertically aligned porous structure, LMZA not only achieves an outstanding evaporation rate at different incident angles and intensities, but also utilizes wind or environmental energy for evaporation. More importantly, the proposed LMZA also achieved a fast evaporation rate of 8.47 kg m-2h−1 under 4.0 m s−1 without solar irradiation, which fully eliminated the impact of solar intermittency. Afterward, LMZA with a cross-scale hierarchical structure for desalination exhibits an evaporation rate of up to 2.08 kg m-2h−1 under one sun irradiation in 20 wt% brine, and possesses exceptional adaptability and stability. Besides, another advantage of LMZA is the effective purification of cadmium-containing wastewater through water evaporation and in situ adsorption. The removal efficiency is 74 % under one sun irradiation, and the condensed water with undetected Cd(II) heavy metal ions was obtained. More importantly, combined with ambient factors such as wind and ambient temperature in the natural environment, the home-made device achieves all-day freshwater generation with a daily yield of 27.08 kg m−2. The investigation of the device and LMZA pioneers a novel design concept for high yield freshwater generation in practical applications.

Coexisting single-atomic Fe and Fe2O3 on nitrogen-deficient g-C3N4 with enriched Fenton-like oxidation and photocatalytic performances for tetracycline degradation: DFT calculation, degradation mechanism and toxicity evaluation

The regulation of heterogeneous material properties to strengthen the peroxymonosulfate activation to destroy refractory pharmaceuticals remains a challenge. Herein, a promising nitrogen-deficient catalyst (FeCN) with single atom Fe and Fe2O3 nanoparticles dispersing on g-C3N4 matrix was synthesized and applied as a competent peroxydisulfate (PDS) activator for tetracycline (TC) degradation under visible light. The K-edge X-ray absorption fine structures and 57Fe Mössbauer measurements confirmed the unique configuration of Fe2O3 and single atom Fe active sites (pyrrolic and pyridinic FeN4) induced by the neighbouring nitrogen vacancies. The theory calculations and experiments provided a deep insight into the PDS activation and TC degradation via radical and non-radical pathways. The pyrrolic FeN4 active sites dominated the electron transfer, while the pyridinic FeN4 and Fe2O3 decomposed PDS to produce free radicals. The synergistic effect between the Fenton-like oxidation and photocatalysis is responsible for efficient TC degradation. This study offers a new strategy by integrating novel catalysts and advanced oxidation technology for effective wastewater purification.

Parabolic trough concentrator design, characterization, and application: solar wastewater purification targeting textile industry dyes and pharmaceuticals—techno-economic study

AbstractSolar energy, along with other renewable resources, has the potential to be a major contributor to solving environmental issues in the future, as illustrated by the most recent advancements in solar photocatalytic technology. Indeed, wastewater treatment using a parabolic solar collector for industrial processes is gaining ground owing to improved system performance and economic benefits. The fabricated parabolic trough collector (PTC) incorporates reflective, parabolic panels that focus solar energy onto a transparent tube positioned along the parabolic focal line, where solar-powered photochemical reactions occur. This study investigated the design, implementation, and effectiveness of a concentrated sunlight system for removing industrial dyes and emerging large-use pharmaceutical contaminants in the presence of H2O2 at a small demonstrator scale (10 L/h). A spectrophotometric assessment revealed that subjecting Remazol Brilliant Blue (RBB, 60 ppm) and ciprofloxacin (CIP, 10 ppm) to irradiation in the presence of 0.1 M H2O2 (RBB) or 0.01 M H2O2 (CIP) for 3 h resulted in a degradation rate exceeding 60% and 80%, respectively. Furthermore, the total organic content (TOC) analysis indicates a very high total removal yield for RBB. On these bases, a techno-economic analysis is produced, and economic viability is discussed. The data reveal that the annual costs for water treatment, considering investment, electricity, and catalyst expenses over a 12-month period are significantly lower for our PTC-based prototype than for a comparable artificial UV-based equipment.

One-step fabrication of millimeter-scale hollow vesicles with chitosan /DADMAC/ sodium alginate graft copolymer for enhanced anionic dye adsorption

Hollow vesicles are promising in water treatment due to their unique structure of the membrane and inner cavity. However, the adsorption capacity needs to be improved for targeted pollutants. Herein, millimeter-scale hollow vesicles were prepared with a one-step process of sequential stirring and grafting using chitosan, diallyldimethylammonium chloride, and sodium alginate as raw materials with the purpose of efficient removal of anionic dyes from wastewater. The composite vesicles were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The hollow vesicles showed the structure of the cationic membrane and the inner cavity, facilitating the dye adsorption. The adsorption capacity for the anionic dye Reactive Black 5 reached 698.1 mg/g, more than twice that of the binary composite vesicles without graft. The adsorption kinetics and isotherm data coincided with the pseudo-second-order and Langmuir models, respectively, and the adsorption mechanism was monolayer chemisorption. Moreover, the vesicles worked well in wide ranges of environment pH, temperature, and co-existing pollutants. They also possessed excellent cyclic regeneration performance, in which 93 % of the initial adsorption capacity was maintained after four cycles. These results indicate that the millimeter-scale hollow vesicles exhibit broad application prospects for wastewater purification.

Review on recent advancements of 2D MXene-based nanostructures on different possible approaches for wastewater treatment

In this review, a brief perspective of MXene (since 2011) with recent research for new and advanced applications for wastewater treatments through various approaches have been discussed. Current information’s about MXenes are summarized to fully understand their nature, promising properties and reduce the challenges that have opened the new era of their uses. Primarily, the existing modest problem is the availability of potable water to sustain healthy human-chain and entire ecosystem, as contaminated water has harsh consequences and poses serious threats to human-health worldwide. In the current stage, supply of potable water for society with cheap and low-cost technology has become the key requirement for the growing economy. Efficient techniques to remove several contaminants (including dyes, heavy metal ions, pharmaceutical or organic products) from wastewater have been transformed gradually to mitigate this scarcity. In this direction, MXene based nanostructures have become a promising material for the wastewater treatment. These structures have unique hydrophilicity, high surface area, a good photocatalytic activity, and wonderful adsorption capacity for contaminates. Numerous advanceshavebeen observed in the optimized rational designs of MXene-derived nanocomposites and their applications in wastewater purification. Hence, timely updates are necessary to emphasize on toxic removals and characterizations including merits and demerits of these MXene-based nanostructures. Thus, this study summarizes the guidelines for the synthesis and applications of MXene-based nanocomposites in wastewater purification, which may stimulate the scientific community to develop a variety of MXene-derived nanostructures with well-defined structures, constitution, and enhanced physicochemical properties for effectively removal of noxious pollutants from wastewater using cost-effective and feasible techniques.

Detailed investigation of the catalytic abilities and adsorption curves of Banana peel with Nanodendrite Silver Nanoparticles for Wastewater purification

Detailed investigation of the catalytic abilities and adsorption curves of Banana peel with Nanodendrite Silver Nanoparticles for Wastewater purification

In situ polymerization of acrylamide on magnetic SnFe2O4/CeO2 nanocomposite: A novel adsorbent for removing various dyes

Environmental conservation requires effective, secure, and economical treatment options for dye-contaminated wastewater. The current study comprises a novel fabrication of tin ferrite/ceria/polyacrylamide magnetic and porous ternary nanocomposite. This occurs through crosslinking polymerization of acrylamide on the SnFe2O4/CeO2 binary nanocomposite. The SnFe2O4/CeO2/PAM nanocomposite was comprehensively characterized using FTIR, TGA, XRD, TEM, VSM, EDX, SEM and N2 adsorption-desorption isotherms. The ternary nanocomposite's efficiency as a novel adsorbent for anionic (direct violet 4, DV4) and cationic (bismarck brown r, BBR) azo dyes was investigated. A range of variables were studied to optimize the effectiveness of eliminating both dyes. In an acidic medium, DV4 removal was more efficient, whereas BBR removal was higher in an alkaline environment. Non-linear regression was employed to analyze adsorption kinetics and isotherm models, using three statistical error functions to determine the best-fit models. Adsorption data for both dyes demonstrated a good conformity with pseudo-second-order and Freundlich isotherm models. The dyes' adsorption was both endothermic and spontaneous. The nanocomposite displayed notable performance throughout five reuses. Moreover, the nanocomposite shows good adsorption efficiency for various dyes (congo red, acid blue 40, methyl green, and crystal violet) as well as DV4 and BBR. Therefore, it emerges as a promising adsorbent for wastewater purification.